A New Method to Identify the Critical Velocity to Protect Stationary Bed Development for Highly Deviated Wells

Highly deviated wells are widely used in the development of marine oilfield, old oilfield and low permeability oilfield. However, during the drilling process, cuttings bed is often formed in the highly deviated section, which affects rate of penetration and downhole safety, and restricts the development of drilling technology of the highly deviated wells. Therefore, the critical velocity to protect stationary bed development(CVPSB)was studied to overcome the shortcoming of the critical velocity to protect bed development(CVPB). This paper advanced a new method to identify CVPSB, developed two-layer model and three-layer model, and analyzed the effect of different parameters including hole angle, cutting diameter, ROP etc on the CVPSB. This paper may serve as a guideline for controlling parameters in drilling and choosing model in developing cuttings bed software.